I think we clearly both agree that mass surveillance is problematic regardless of whether it is done by the government or corporations. With that said
> normies would probably say it shouldn't be allowed
Despite knowing about this, most continue supporting the various companies doing exactly that, like Facebook and Google.
> Neither is there an expectation [...]
Expectation is not law, and it cuts both ways. The authors of the 4th and 5th amendments likely did not anticipate the existence of encryption - in their view, the flip side of the 4th amendment is that with a warrant, the government could search anything except your mind, which can't store that much information. We now get to enjoy an almost absolute right to privacy due to the letter of the law. You might feel that we should have that right anyway, but many other governments with a more recent/flexible constitution do not guarantee that, and in fact require key disclosure.